Schematic representation of the experimental design.

Novel tank test (NTT) of fish kept for 75 days in standard conditions (control), enriched environment (EE), or under chronic stress (CS). Data of absolute turn angle (A), total time immobile (B), time in the top zone (C), latency to the top zone (D), and in the bottom zone (E). Data from panels A, C, and E are expressed as mean ± SEM and analyzed by ANOVA followed by Tukey’s post-hoc test. Data from panels B and F are expressed as median ± interquartile range and analyzed by Kruskal–Wallis test followed by Dunn’s test (n = 9–14). *p < 0.05; **p < 0.01; and ***p < 0.001. ANOVA, analysis of variance; SEM, standard error of mean.

Shoaling test (ST) of fish kept for 75 days under standard conditions (control), enriched environment (EE), or chronic stress (CS). Data expressed as median ± interquartile range (panel B) and analyzed by Kruskal–Wallis test followed by Dunn’s test (n = 9–14). ****p < 0.0001.

Redox status of fish kept for 75 days under standard conditions (control), enriched environment (EE), or chronic stress (CS). TBARS levels in muscle (A), and brain (E) tissue. Catalase (CTL) activity in muscle (B), and brain (F) tissues. Glutathione-S-transferase activity (GST) in muscle (C), and brain (G). Superoxide dismutase activity (SOD) in muscle (D), and brain (H). Data expressed as mean ± SEM (panel A) and analyzed by ANOVA followed by Tukey’s post-hoc test (panel B) and in median ± interquartile range (panels A, C, D, E, F, G, and H) and analyzed by Kruskal–Wallis test followed by Dunn’s test (n = 9–14). *p < 0.05; **p < 0.01; ***p < 0.001 and ****p < 0.0001. TBARS, thiobarbituric acid reactive substances.